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Pulse shaping methods for inter carrier interference reduction in OFDM system N. M. A. E. D. Wirastuti; Ni Putu Lintang Anggitiadewi; Nyoman Pramaita
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 18, No 5: October 2020
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v18i5.13840

Abstract

The weakness of the orthogonal freuency division multiplexing (OFDM) system is susceptible to the existence of carrier frequency offset (CFO) which causes the emergence of inter carrier interference (ICI) which causes a degradation of performance OFDM systems. This study aims to apply the suggested rectangular (REC) pulse and improved sinc-power (ISP) pulse shaping methods on OFDM system and determines ICI reduction with the effects of CFO over flat fading Rayleigh channels. The performance of each pulse shaping method is evaluated and compared based on parameter ICI power vs. normalized frequency offset, signal to interference ratio (SIR) vs. normalized frequency offset and bit error rate (BER) vs. energy bit per noise (Eb/No). The simulation result in terms of BER vs. Eb/No indicated that REC and ISP pulse shaping has better performance dealing with ICI reduction compared to OFDM system no applied pulse shaping. In addition, the ISP is able to mitigate ICI better than REC.
DESAIN PROGRAM SIMULASI UNJUK KERJA KODE LARGE KASAMI PADA SISTEM KOMUNIKASI DIRECT SQUENCE SPREAD SPECTRUM MELALUI KANAL MULTIPATH FADING I Ketut Widi Arjana Yasa; Nyoman Pramaita; Ni Made Ary Esta Dewi Wirastuti
Jurnal SPEKTRUM Vol 8 No 3 (2021): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (635.899 KB) | DOI: 10.24843/SPEKTRUM.2021.v08.i03.p7

Abstract

Selection of Pseudo Noise (PN) code in CDMA multiple access is needed to overcomeproblems related to interference. In this study, we simulate the large kasami code with the aimof knowing the performance of the large kasami code on flat fading channels and frequencyselective fading channels with variations in the number of multipath components. The receiversystem uses a correlation receiver to correlate the code used by each user. The simulationresults from the performance of the large kasami code through the flat fading channel show thatthe simulation carried out is valid, where the simulation BER value is close to the flat theoreticalBER value. The frequency selective fading channel shows different BER values from variationsin the number of multipath components, where the multipath 60 component produces the worstBER value. Auto correlation code large kasami has a value when the time is not equal to zerowhich can interfere with the desired signal and there is a cross-correlation signal level value thatwill interfere with each other's users.
RANCANG BANGUN SISTEM PENDETEKSI KEBAKARAN HUTAN BERBASIS NODE MCU ESP8266 I G A Ari Kukuh Sentanu; I Gst A. Komang Diafari Djuni; Nyoman Pramaita
Jurnal SPEKTRUM Vol 8 No 1 (2021): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (243.781 KB) | DOI: 10.24843/SPEKTRUM.2021.v08.i01.p32

Abstract

The problem that often occurs so far is the delay in the presence of the fire departmentat the fire site. So the authors make an early detection tool for forest fires based on the Internetof Things because forest fires occur in very large forests so that supervision from officers is notenough. This study aims to design a forest fire extinguishing system based on ESP8266NodeMCU. The research was conducted by designing a system and making it happen by usinga board and several sensors to obtain data. From the results of the design carried out in thisstudy, the prototype of forest fire detection systems based on NodeMCU ESP8266 andtemperature, fire and smoke sensors has been realized, which can send notifications ontelegram. And the pump can put out the fire. The actual application in the forest still needschanges to the pump construction and the addition of several sensors.
DESAIN SIMULASI UNJUK KERJA KODE SMALL KASAMI PADA KANAL MULTIPATH FADING I Kadek Adi Wiguna Sanjaya; Nyoman Pramaita; I Made Oka Widyantara
Jurnal SPEKTRUM Vol 8 No 3 (2021): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (554.009 KB) | DOI: 10.24843/SPEKTRUM.2021.v08.i03.p4

Abstract

Telecommunication capable of handling interference, fading and no less importantissues regarding the confidentiality of user information is very much needed in the currenttechnological era, to overcome this spread spectrum technology is quite developed in theadvancement of telecommunication technology. In this study, the small kasami code was usedas the spreading code. The purpose of this study is to determine the performance of the smallkasami code with changes in the number of multipath components using multipath fadingchannels. The modulation technique uses digital modulation, namely binary phase shift keying(BPSK) with a small kasami code with a code length of 15 in the spreading and spreadingprocess. Analyzed based on BER (Bit Error Rate) versus EB/No (Energy Bit per Noise). In thesimulation of flat fading performance using 1 multipath component, flat fading serves as an idealreference where the simulation BER should resemble the theoretical BER as simulationvalidation so that it can be used on selective fading channels. Variation of multipathcomponents in frequency selective fading channel produces different BER because there isinterference of multipath signal to the desired signal. The number of multipath components asmany as 11 have the most interference signals resulting in the worst performance. The value ofcross correlation between users has poor performance, where the correlation value of user 1with 2, 3, and 4 is more than 0, this value shows that many signal levels experience interferencebetween users.
PENYELEKSI BARANG BERDASARKAN TINGGI BERBABIS MICROCONTROLLER ATMEGA 8535 DENGAN KONVEYOR I Gede Krisnu Wardana; Nyoman Gunantara; Nyoman Pramaita
Jurnal SPEKTRUM Vol 6 No 1 (2019): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (200.572 KB) | DOI: 10.24843/SPEKTRUM.2019.v06.i01.p03

Abstract

Problems that often occur in the selection of goods, there are still many industries that make convey-ors as senders only without a selection process. The purpose of this study was to make a high-variable item selection prototype tool using an ATMega 8535 microcontroller. It was found that the prototype goods se-lection tool was based on a high ATMega 8535 microcontroller with a maximum working conveyor. Con-veyor 1 will move if there is an item or object that is left in front of conveyor 1 and stops the goods at the end of the conveyor 1. Conveyor 2 will move if the photodiode sensor has detected the items on the convey-or 1. All tests are performed properly. The photodiode sensor works well to measure the height of objects or items. Further improvements with more complex development prototypes that can be applied to actual industries and factories. This tool can only measure the height of the item from what can be developed or the weight of the item.
DESAIN PROGRAM SIMULASI PENERAPAN KODE BOSE CHAUDHURI HOCQUENGHEM PADA DIRECT SEQUENCE SPREAD SPECTRUM M. Husnul Ullum Azhari; Nyoman Pramaita; I Gst A. Komang Diafari Djuni H
Jurnal SPEKTRUM Vol 7 No 4 (2020): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (529.037 KB) | DOI: 10.24843/SPEKTRUM.2020.v07.i04.p8

Abstract

This study proposes a design of simulation program for implementing Bose ChaudhuriHocquenghem (BCH) code on Direct Sequence Spread Specterum (DSSS) to knowing theperformance of the effect of DSSS with flat fading channel and AWGN without BCH code (7,4)with the application of BCH code (7,4) on DSSS with flat fading and AWGN channel. Thissimulation consist of simulation of BER application of BCH code (7,4) on DSSS with flat fadingand AWGN channel, simulation of BER application code BCH (7,4) on DSSS with AWGNchannel, simulation of the effect of Eb/No on noise variance in the DSSS system, and BERsimulation as a function of noise variance on the DSSS system. Simulation of application BCHcode (7,4) on DSSS with flat fading and AWGN channel analyzed based on Bit Error Rate(BER) versus Energy Bit per Noise (Eb/No). The application of BCH code (7,4) on DSSS withflat fading channel and AWGN shows better performance than DSSS with flat fading channelsand AWGN without BCH coding (7,4). On the Eb/No value 10 dB, simulation application BCHcode (7,4) on DSSS with flat fading channel and AWGN generate BER value which isapproaching 0 with BER value 0.0188, while the DSSS simulation with flat fading channel andAWGN without BCH code (7.4) generate a BER value of 0.0228.
SIMULASI KINERJA GOLD CODE PADA SISTEM KOMUNIKASI DIRECT SEQUENCE SPREAD SPECTRUM (DSSS) MELALUI KANAL MULTIPATH FADING Muhamad Zainul Halim; Nyoman Pramaita; Pande Ketut Sudiarta
Jurnal SPEKTRUM Vol 8 No 2 (2021): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (429.736 KB) | DOI: 10.24843/SPEKTRUM.2021.v08.i02.p29

Abstract

The communication channel cannot be separated from noise, interference and fading.To minimize mutual interference, you can use a scatter code. This research uses Gold Codewith a code length of 31. This simulation aims to determine the effect of the number of multipathcomponents on the Gold Code performance of multipath fading channels. This simulation usesdigital modulation, namely BPSK (Binary Phase Shift Keying). In the simulation of flat fadingchannel with 1 multipath component number, the results of the comparison of simulated BERwith theoretical BER are almost the same so that the simulation results can be said to be validand can be used on selective fading channels. In the simulation of frequency selective fadingchannels with variations of multipath components have different values, this happens due tointerference. In this simulation, the number of multipath 27 components that have the mostdisruptive signals results in the worst performance. In multi-user cross-correlation, it has poorperformance, seen from the cross-correlation function, where the correlation value of user 1with 2, 3 and 4 is more than 0, this value indicates the user is being interfered with by otherusers.
SISTEM NOTIFIKASI SWITCH BERBASIS TEKNOLOGI WIRELESS Janice Jessica Indrayani; Nyoman Pramaita Nyoman Pramaita; I Made Oka Widyantara
Jurnal SPEKTRUM Vol 8 No 1 (2021): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (313.722 KB) | DOI: 10.24843/SPEKTRUM.2021.v08.i01.p22

Abstract

This research develops a remote switch notification system by utilizing radio waves. This system will usethe RF433 module and RF315 module as the transmission medium, the HT12E module as the encoderand the HT12D module as the decoder. The working principle of the system is that the sending partsends a signal when the voltage is applied via a push button, then the switch is sent to the part of theroom and activate the relay. Then in the relay there is also an encoder that will recode the data on therelay that the relay is active and resend the data to false senders so that the LED as notification will turnon. Based on the test results it is known that the remote switch notification system that has beendesigned is able to turn on and turn off the relay and also be able to transmit the notification properly.
ANALISIS KINERJA KOMBINASI SISTEM CODE DIVISION MULTIPLE ACCESS MULTIPLE INPUT MULTIPLE OUTPUT DENGAN KODE PENEBAR WALSH PADA KANAL RAYLEIGH FADING I Gd. Tri Dharma Prawira; I.G.A.K. Diafari Djuni Hartawan; N. Pramaita
Jurnal SPEKTRUM Vol 5 No 2 (2018): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (496.856 KB) | DOI: 10.24843/SPEKTRUM.2018.v05.i02.p36

Abstract

The increasing human population are same to the need for telecommunications. Code Division Multiple Access (CDMA) is one of the most widely used telecommunications technologies. But with the increasing number of users, this technology is no longer able to meet the needs of users. With the required capacity requirements, the CDMA system and Multiple Input Multiple Output (MIMO) technology are merged.To find out the performance of a combined CDMA MIMO system, the system was tested by increasing the number of users and Signal to Noise Ratio (SNR) where the spreading code used was the Walsh code and the channel used was Rayleigh Fading modeling. The reference value used as material for consideration are the value of Bit Error Rate (BER).The method used in testing the CDMA MIMO system is the increase number of users, starting with a single user up to 16 users and SNR values from -15 dB to a maximum of 15 dB.Where all users will be combined with the CDMA technique then it will be sent using MIMO technology. The system will be tested using a simulation of the MatLab R2012a software.The results of the simulation show the performance of the CDMA MIMO system when using SNR that is increasing high, the BER will be lower or better used for communication. Whereas for simulations using a user that increases it results in a BER value that is almost the same because of the nature of the orthogonal Walsh code so that each user does not experience interference with other users.
DESAIN JARINGAN HOTSPOT FAKULTAS TEKNIK UNIVERSITAS UDAYANA BUKIT JIMBARAN MENGGUNAKAN STANDARD IEEE 802.11N OUTDOOR DENGAN KUALITAS VOIP Komang Diyana Putra; Pande Ketut Sudiarta; Nyoman Pramaita
Jurnal SPEKTRUM Vol 6 No 4 (2019): Jurnal SPEKTRUM
Publisher : Program Studi Teknik Elektro UNUD

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (637.953 KB) | DOI: 10.24843/SPEKTRUM.2019.v06.i04.p11

Abstract

Fakultas Teknik Universitas Udayana memiliki area outdoor yang cukup luas, maka dari pada itu dibutuhkan penelitian dalam melakukan desain jaringan untuk area outdoor pada kawasan Fakultas Teknik Universitas Udayana Bukit Jimbaran. Pada paper ini menganalisis jangkauan WLAN kondisi outdoor dengan kualitas VoIP. Aplikasi yang digunakan adalah G-NET Wi-fi, Terminal Emulator dan menggunakan software Atoll. Dalam melakukan penelitian, diawali dengan melakukan pengukuran level sinyal dari AP dengan rentang jarak 3 meter dari AP dilanjutkan ke jarak 6 meter dan seterusnya sampai titik dimana tidak dapat melakukan komunikasi antara AP dengan Reciever. Berdasarkan hasil analisis kondisi jangkauan area Voip yang dilakukan di wilayah Fakultas Teknik Univrsitas Udayana, mendapatkan kondisi dimana level sinyal pada masing- masing jarak mendapatkan hasil yang berbeda dengan hasil ukur. Dengan mengacu pada penelitian yang telah dilakukan, diperlukan penambahan AP di kawasan Fakultas Teknik Universitas Udayana Bukit Jimbaran, diperlukan 34 AP pada kawasan Fakultas Teknik Utama dan 13 AP untuk kawasan fakultas teknik sipil.